Usage statistics: 4.00/8.00 GB Bug?

I hope somebody will be able to help me.
A friend of mine asked me how she could check for her monthly generated traffic, as she moved for study purposes and her current internet connection is limited to 2 GB per month.
So I checked for an easy to use and free tool which I could explain her how to install and use. I found Networx and this is exactly what she needs.

Anyway, there is unfortunately no happy end yet, because she discovered a bug, which is very annoying. Every time she puts her laptop in standby or hibernation, and starts it up again, the counter is set to 4.00 GB received and 4.00 GB sent, so 8.00 GB in total. The value will not change anymore, so it will stay 8.00 GB exactly, even if there is traffic on the NIC. The only way to sort it out is to reset the counter.

I tried to reproduce the problem on my own notebook, but there it works correctly.
I now assume the problem either comes from her specific NIC (maybe a driver incompatibility with the tool, or similar?) or from the fact that she is using Windows Vista (I tested it on XP).

I advised her to turn off the Networx app before going to standby/hibernation, and to launch it manually once the laptop is turned on again. This does help, but if she forgets to end the app once, her statistics will be messed up again..

Did somebody encounter the same problem and/or does even know if it can be solved?
If I do not find a solution for that problem, there is a high danger of life for me personally, so I'd be glad to have some feedback!

Thank you for the detailed description of the problem. There was a bug that could cause a sudden jump in the numbers. We have just fixed it in v4.1.1, so please download the update here and install it over your already installed copy.